小菜蛾对阿维菌素的抗性机制及交互抗性研究

用叶片药膜法研究了阿维菌素抗性小菜蛾 Plutella xylostella （L.）品系 对常用药剂的交互抗性谱以及增效醚（PB）和磷酸三苯酯（TPP）的增效作用。小菜蛾对阿 维菌素与高效氯氰菊酯、溴氰菊酯、氰戊菊酯和联苯菊酯等菊酯类药剂间具有比较低的交互 抗性，对后者抗性为3～20倍，对阿维菌素的抗性为575.6倍；对氟虫脲和氟啶脲没有交互抗 性。PB和TPP对阿维菌素分别增效8.2和5.5倍，说明小菜蛾对阿维菌素的抗性可能与多功能 氧化酶（MFO）和羧酸酯酶有关。通过差光谱技术测定了阿维菌素抗性和敏感小菜蛾细胞色 素P450的含量，抗性品系是敏感品系的1.38倍。

Stuy on Resistance Machanisms and Cross-Resistance of Abamectin in Diamondback Moth Plutella oxylostella (L.)

Synergism of abamectin(AVMs) by piperonyl butoxide (PB) and TPP in both AVMs-resistant(AV-R) and susceptible(XH-S) strains of diamondback moth ［DBM, Plutella oxylostella (L.)］ was investigated. Both PB and TPP increased the toxicity of AVMs to AV-R strain and the synergism ratios are 8.2- and 5.5-folds, respectively, but they all have no effect on the toxicity of AVMs to XH-S strain. It suggested that the high resistance to AVMs in DBM is correlated to carboxylesterase and mixed functional oxidase(MFO), which was verified by the comparison of cytochrome P450 content between these two strains. The cross-resistance of AVMs to pyrethroid insecticides and insect growth regulators was also studied in AVMs-selected strains. AVMs-selected strains possessed the low cross-resistance between four pyrethroid insecticides tested and abamectin, but no cross-resistance to two insect growth regulators, flufenoxuron and chlorfluazuron.